Most present biosensors take advantage of biologically active materials for high sensitivity and selectivity. In general, these biosensors include a bio-recognition structure (e.g., a membrane) in contact with or interrogated by a transducer. The biologically active material recognizes a particular biological molecule through a reaction, specific adsorption, or other physical or chemical process, and the transducer converts the output of this recognition into a usable signal, usually electrical or optical. Many approaches have been explored to achieve ultra-sensitive detection of bio-species. These biodetection approaches can be categorized as either an engineering-oriented approach or a biological-oriented approach. In other words, most biodetection schemes are either based on relatively complex electronic, photonic and/or electrochemical methods or on more elegant biomolecular methods (e.g. enzyme linked immunosorbent assay, or ELISA) typically with an optical or spectrometry-based readout. In view of the foregoing, there has been an enormous effort in recent years to develop practical and cost-effective biosensors.
In seeking a solution to a human problem, scientists often turn to nature. For example, one fascinating aspect associated with certain plants is the rapid motion of such plants by a process called “explosive fracture.” The explosive fracture of a plant involves rapid geometric changes of the plant that are induced by the tearing motion of the plant tissue for seed or sporangium dispersal. The rate of fracture explosion is significantly faster than that of the swelling motion of the plant tissue by several orders of magnitude due to the elastic instability of the plant tissue. As a result of this elastic instability, a critical point is reached when the plant's stored elastic energy overcomes constriction of the plant tissue, thereby inducing a high energy explosion. It can be appreciated that the fracture motion is easily detectable by the naked eye due to the dramatic changes in geometry. Hence, it is highly desirable to provide a method and device for detecting a material that mimics the explosive fracture of certain plants in order to generate a visual display for a user.
Therefore, it is a primary object and feature of the present invention to provide a method and device for detecting a material that is highly sensitive and selective, has a quick response time and generates few false alarms.
It is a further object and feature of the present invention to provide a method and device for detecting a material that is simple to use and is inexpensive to manufacture.
It is a still further object and feature of the present invention to provide a method and device for detecting a material that generates an easily observable signal to a user to indicate the presence of the material.
In accordance with the present invention, a detection device is provided for detecting a predetermined material. The device includes a first inner layer having first and second surfaces and a volume responsive to a first predetermined stimuli. The device also includes a second inner layer having first and second surfaces. An adhesive bonds at least a portion of the first surface of the first inner layer to the first surface of the second inner layer with a bonding force. A change in the volume of the first layer generates an elastic force on the adhesive material. The first inner layer delaminates from the second inner layer in response to the elastic force overcoming the bonding force.
The second inner layer has a volume responsive to the predetermined stimuli. In addition, the device also includes a first outer layer bonded to the first inner layer and having a volume responsive to a second predetermined stimuli. A second outer layer is bonded to the second inner layer and has a volume responsive to the second predetermined stimuli. A clip has a first end operatively connected to the first outer layer and a second end operatively connected to the second outer layer. The adhesive degrades in response to exposure to the predetermined material. It is contemplated for the first predetermined stimuli to be the predetermined material. The first and second inner layers include first and second ends. The adhesive is located adjacent the first ends of the first and second inner layers. A sheet, which does not bind with the inner layers, may be positioned between the first and second inner layers to reduce the bonding area so as to achieve faster reaction of the device.
In accordance with a further aspect of the present invention, a sensing mechanism is provided. The sensing mechanism includes a first inner layer having first and second surfaces and first and second ends. The first inner layer also has a volume responsive to a first predetermined stimuli. A second inner layer has first and second surfaces and first and second ends. The second inner layer also has a volume responsive to the first predetermined stimuli. An adhesive bonds the first surface of the first inner layer to the first surface of the second inner layer with a bonding force at a location adjacent the first ends of the first and second inner layers. Changes in the volumes of the first and second layers generate an elastic force on the adhesive material. The first inner layer delaminates from the second inner layer in response to the elastic force overcoming the bonding force.
A first outer layer is bonded to the first inner layer and has a volume responsive to a second predetermined stimuli. A second outer layer is bonded to the second inner layer and having a volume responsive to the second predetermined stimuli. A clip has a first end operatively connected to the first outer layer and a second end operatively connected to the second outer layer. The adhesive degrades in response to exposure to a predetermined material. A sheet is positioned between the first and second inner layers.
In accordance with a still further aspect of the present invention, a method of sensing for use in detecting a material is provided. The method includes the steps of interconnecting first and second inner layers with an adhesive and exposing the first and second inner layers to a solution. The first and second layers separate in response to material in the solution.
A first outer layer is bonded to the first inner layer and a second outer layer is bonded to the second inner layer. The first and second outer layers are interconnected with a clip. The adhesive degrades in response to exposure to the material and the first and second inner layers have a volume responsive to a predetermined stimuli. It is contemplated for the predetermined stimuli to be the material. The first and second inner layers generate an elastic force in response to the predetermined stimuli. The adhesive interconnects the first inner layer to the second inner layer with a bonding force. When the elastic force is greater than the bonding force in response to material in the solution, the first and second layers separate. A sheet may be positioned between a portion of the first and second inner layers.